JP2015133574A - Interdigital electrode, formation method of interdigital electrode, and device using interdigital electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interdigital electrode that can be formed conveniently, while thinning the line width of electrodes constituting the interdigital electrode sufficiently, and to provide a formation method of an interdigital electrode and a device using an interdigital electrode.SOLUTION: In an interdigital electrode combining comb-like electrodes and opposite comb-like electrodes on a substrate 1, the comb-like electrodes are formed by a method for forming a parallel line pattern containing a conductive material in self-organization by controlling the dry process, after forming the lines by giving a conductive material-containing liquid.

Description

  The present invention relates to a comb-shaped electrode, a method for forming a comb-shaped electrode, and a device using the comb-shaped electrode. More specifically, the comb-shaped electrode can be easily formed, and the line width of the electrode constituting the comb-shaped electrode is sufficiently thin. The present invention relates to a comb electrode, a method of forming a comb electrode, and a device using the comb electrode.

  In various devices, comb-shaped electrodes (also referred to as interdigital electrodes) are used.

  For example, a piezoelectric material formed with a comb electrode is used as a surface acoustic wave (SAW) filter.

  Surface acoustic wave elements have begun to be used as filters for television receivers, beginning with applications for radar, and are recently widely used in filters for mobile communication devices.

  These conventional comb-shaped electrodes are generally formed by a photolithography process since the interval between comb teeth is generally on the order of μm.

  The comb-shaped electrode can also be used as an electrode for a capacitor (Patent Document 1).

JP 2004-72034 A

  The conventional photolithography process has many steps, and it is difficult to easily form a comb-shaped electrode.

  Although it is conceivable to form a comb electrode by a printing method, it has been difficult to make the line width of the electrode sufficiently narrow.

  Accordingly, an object of the present invention is to provide a comb-shaped electrode, a method for forming a comb-shaped electrode, and a device using the comb-shaped electrode, in which a comb-shaped electrode can be easily formed and the line width of the electrode constituting the comb-shaped electrode can be made sufficiently narrow Is to provide.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

1.
A comb-shaped electrode combined with a comb-shaped electrode and a comb-shaped counter electrode so as not to be coupled to each other on a substrate,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process Comb-shaped electrode characterized by utilizing.

2.
2. The comb-shaped electrode according to 1 above, wherein an insulating material layer is inserted between the opposite electrodes so that the opposite electrodes are not bonded to each other.

3.
2. The comb-shaped electrode according to claim 1, wherein the parallel line patterns are spaced apart from each other so that the opposite electrodes are not coupled to each other.

4).
A comb-shaped electrode combined with a comb-shaped electrode and a comb-shaped counter electrode so as not to be coupled to each other on a substrate,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process A method of forming a comb-shaped electrode, which is characterized by being utilized.

5.
5. The method for forming a comb-shaped electrode as described in 4 above, further comprising a step of arranging the insulating material layer so as to be inserted between the opposite electrodes so that the opposite electrodes are not coupled to each other.

6).
A device comprising the comb electrode according to any one of 1 to 3 above.

7).
A surface acoustic wave device comprising a plurality of comb electrodes on a piezoelectric substrate,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process A surface acoustic wave device characterized by being utilized.

8).
A gas sensor comprising a plurality of comb electrodes on a piezoelectric substrate, and a gas adsorption layer between the plurality of comb electrodes,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process A gas sensor characterized by utilizing it.

9.
A capacitor comprising a comb electrode on a substrate, and a dielectric material layer on the comb electrode,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process Capacitor characterized by utilizing.

  ADVANTAGE OF THE INVENTION According to this invention, the comb-shaped electrode which can form a comb-shaped electrode simply and can make the line | wire width of the electrode which comprises a comb-shaped electrode thin enough, the formation method of a comb-shaped electrode, and the device using a comb-shaped electrode are provided. can do.

Explanatory drawing explaining the 1st aspect of the comb-shaped electrode formation method (1st) Explanatory drawing explaining the 1st aspect of the comb-shaped electrode formation method (2nd) Explanatory drawing explaining the 1st aspect of the comb-shaped electrode formation method (3rd) Sectional view taken along line iv-iv in FIG. Explanatory drawing explaining an example of the shape of a parallel line pattern Explanatory drawing explaining the 2nd aspect of the comb-shaped electrode formation method (1st) Explanatory drawing explaining the 2nd aspect of the comb-shaped electrode formation method (2nd) The top view which shows an example of the surface acoustic wave element of this invention The top view which shows an example of the sensor of this invention The top view which shows an example of the capacitor | condenser of this invention

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1-3 is explanatory drawing explaining the 1st aspect of the comb-shaped electrode formation method, and has shown a mode that the base material in which a comb-shaped electrode is formed was planarly viewed.

  As shown in FIG. 1A, a liquid containing a conductive material (hereinafter sometimes simply referred to as a conductive material-containing liquid) is applied on the base material 1. Thus, the first line 2 made of the conductive material-containing liquid is formed on the substrate 1. In the illustrated example, a plurality of (three in the illustrated example) first lines 2 parallel to each other are formed.

  In this specification, the length direction of the line 2 is referred to as the X direction, and the line width direction of the line 2 is referred to as the Y direction.

  The plurality of lines 2 are provided at a predetermined pitch in the Y direction. Moreover, it is preferable that the line width of each of the plurality of lines 2 and the gap between the lines 2 adjacent in the Y direction are substantially equal.

  Next, the first wire 2 is dried. That is, the liquid in the conductive material-containing liquid constituting the first line 2 is evaporated. At this time, in the drying process, the conductive material in the conductive material-containing liquid is deposited on the edge in a self-organized manner, and a pair of thin wires 31 and 32 parallel to each other are formed as shown in FIG. A first parallel line pattern 3 is formed.

  The method for forming the parallel line pattern including the conductive material in a self-organizing manner by controlling the drying process is not particularly limited. A preferred method will be described in detail later.

  In the first parallel line pattern 3, a pair of thin wires 31 and 32 parallel to each other generated from one first line 2 are closed at both ends. That is, the thin wires 31 and 32 are connected to each other by the end portion 33 on one end side and the end portion 34 on the other end side of the first parallel line pattern 3.

  Next, as shown in FIG. 2A, the insulating layer 4 is formed. In the illustrated example, the plurality of first parallel line patterns 3 are respectively formed in a strip shape so as to cross the plurality of first parallel line patterns 3 in the Y direction on one end side and the other end side in the X direction. The one end side insulating layer 41 and the other end side insulating layer 42 are formed. The one end side insulating layer 41 and the other end side insulating layer 42 are made of an insulating material.

  One end 33 of the first parallel line pattern 3 extends to the outer side (left side in the figure) from the position where the one end side insulating layer 41 is formed to form one end side extending portion 35. The other end 34 of the first parallel line pattern is covered with the other end side insulating layer 42.

  Next, as shown in FIG. 2B, a conductive material-containing liquid is applied on the base material 1. Thus, the second line 5 made of the conductive material-containing liquid is formed on the base material. In the illustrated example, a plurality of (in the illustrated example, three) second lines 5 that are parallel to each other are formed.

  The conductive material-containing liquid for forming the second line 5 is similar to the conductive material-containing liquid for forming the first line 2 described above in the same conductive material and solvent. It may be different or different.

  The second line 5 is formed for each first parallel line pattern 3 so as to cover one thin line 32 among the parallel thin lines 31 and 32 constituting the first parallel line pattern 3. Yes. The center of the second line 5 in the line width direction is preferably arranged so as to overlap the thin line 32.

  Next, the second line 5 is dried. That is, the liquid in the conductive material-containing liquid constituting the second line 5 is evaporated. At that time, in the drying process, the conductive material in the conductive material-containing liquid is deposited on the edge in a self-organized manner, and a pair of thin wires 61 and 62 parallel to each other are formed as shown in FIG. A second parallel line pattern 6 is formed.

  In the second parallel line pattern 6, a pair of thin wires 61 and 62 parallel to each other generated from one line 5 are closed at both ends. That is, the thin wires 61 and 62 are connected to each other by the end portion 63 on one end side and the end portion 64 on the other end side of the second parallel line pattern 6.

  One end 63 of the second parallel line pattern 6 is disposed on the one end side insulating layer 41. The other end 64 of the second parallel line pattern 6 extends to the outer side (right side in the drawing) from the formation position of the other end side insulating layer 42 to form the other end side extending portion 65.

  The mutually parallel fine lines 31 and 32 constituting the first parallel line pattern 3 and the mutually parallel fine lines 61 and 62 constituting the second parallel line pattern 6 are arranged in parallel.

  The fine lines 31 and 32 constituting the first parallel line pattern 3 and the fine lines 61 and 62 constituting the second parallel line pattern 6 are alternately arranged one by one at equal intervals in the Y direction.

  As shown in FIG. 3B, the first take-out electrode 7 is formed so as to cross the one end side extending portion 35 of the plurality of first parallel line patterns 3 in the Y direction as necessary. . Similarly, the second extraction electrode 8 is formed so as to traverse the other end side extending portion 65 of the plurality of second parallel line patterns 6 in the Y direction.

  As described above, the comb-like electrode composed of the fine lines 31 and 32 constituting the first parallel line pattern 3 and the comb-like electrode composed of the thin lines 61 and 62 constituting the second parallel line pattern 6 are opposite to each other. It is possible to form a comb-shaped electrode combined with the electrode so that the comb-tooth portions are engaged with each other so as not to be coupled to each other.

  The fine lines forming the comb-like electrode and the counter electrode are formed by, for example, photolithography because the conductive material in the conductive material-containing liquid is deposited on the edge in a self-organizing manner during the drying process. It can be formed more easily than in other cases. In addition, the thin line can be made sufficiently thin beyond the limit of thinning by a normal printing method. Thereby, the usage-amount of an electroconductive material can be reduced, for example.

  In particular, in the first aspect of the comb-shaped electrode forming method, the insulating layers 41 and 42 are inserted into the overlapping portion of the first parallel line pattern 3 and the second parallel line pattern 6. Thereby, the fine lines 31 and 32 (comb-like electrodes) constituting the first parallel line pattern 3 and the fine lines 61 and 62 (comb-like counter electrodes) constituting the second parallel line pattern 6 are formed. In addition, it is possible to alternately arrange one by one in the Y direction while keeping them not coupled to each other (while keeping the insulation state). Thereby, it becomes possible to arrange | position an electrode and a counter electrode with high density, and can improve the characteristic of a device more suitably.

  In the first embodiment, the formation positions of the insulating layers 41 and 42 are not limited to the above example, and at least the fine wires 31 and 32 (comb-like electrodes) constituting the first parallel line pattern 3 and The thin wires 61 and 62 (comb-like counter electrodes) constituting the second parallel line pattern 6 may be provided so as not to contact each other at a position where they intersect.

  The method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process is not particularly limited. For example, 1 or 2 such as a method of heating a substrate or an atmosphere or a method of blowing air A combination of the above can be selected.

  Moreover, a drying process can be controlled so that a parallel line pattern may be formed by adjusting the liquid angle provided as a conductive material containing liquid which adjusts the contact angle of a conductive material containing liquid and a base material.

  In this manner, the conductive material in the conductive material-containing liquid can be selectively deposited on the edge of the conductive material-containing liquid in the drying process on the substrate to form a parallel line pattern. The selective deposition of the conductive material on the edge is realized by convection generated in the conductive material-containing liquid during drying, that is, convection from the central portion of the conductive material-containing liquid toward the edge.

  When the parallel line pattern is formed from the conductive material-containing liquid, it is preferable that the conductive material in the liquid does not substantially remain between the fine lines constituting the obtained parallel line pattern. This point will be described in detail later in connection with the thin film portion 30.

  Further, as a method for forming a parallel line pattern, a principle and method known as a so-called coffee ring effect can be used.

  In these methods, since the conductive material in the conductive material-containing liquid is deposited along the edge of the conductive material-containing liquid in the drying process, the two fine lines constituting the parallel line pattern are usually obtained. Are connected to each other at the ends of the thin wires and closed.

  If necessary, it is also preferable to remove the end of the parallel line pattern. The method for removing the end portion of the parallel line pattern is not particularly limited. For example, a method using masking, a method of rubbing partially, a laser ablation method, or the like can be appropriately used. Further, when the end portion of the parallel line pattern is arranged at a position intersecting with another parallel line pattern, it is possible to omit the formation of the insulating layer described above by removing this end portion. .

  Even if the conductive material-containing liquid for forming the next parallel line pattern is applied so as to overlap with the previously formed parallel line pattern formation region as in the first aspect described above, the previously formed parallel line is formed. The shape of the line pattern is sufficiently retained. At this time, it is also preferable to consider so that the shape of the previously formed parallel line pattern is more suitably maintained. A method in which the previously formed parallel line pattern is fixed on the substrate by heating, baking, or heating with electromagnetic waves in advance, or the conductive material contained in the previously formed parallel line pattern is dissolved or dispersed. A method of selecting and using a conductive material-containing liquid that is difficult to cause can be used.

  Next, an example of the shape given to the parallel line pattern will be described with reference to FIG. FIG. 4 is a cross-sectional view taken along the line iv-iv in FIG. 1B, and is a cross-sectional view in which the thin lines 31 and 32 constituting the parallel line pattern 3 are cut in a direction perpendicular to the line segment direction.

  The thin wires 31 and 32 do not necessarily have an island shape completely independent from each other. As illustrated, the thin film portion 30 may be formed between the fine wires 31 and 32 at a height lower than the height of the fine wires 31 and 32. The thin film portion 30 is formed, for example, when the parallel line pattern is formed from the liquid containing the conductive material, and the conductive material in the liquid slightly remains between the thin lines constituting the obtained parallel line pattern. Can be done.

  The line widths W1 and W2 of the thin wires 31 and 32 are preferably 20 μm or less, respectively. Furthermore, it can also be set as the level which cannot be normally visually recognized by setting it as 10 micrometers or less. Considering the stability of the thin wires 31 and 32, the line widths W1 and W2 of the thin wires 31 and 32 are preferably in the range of 2 μm or more and 20 μm or less, respectively.

  Note that the widths W1 and W2 of the thin wires 31 and 32 are Z and the height of the thinnest portion where the thickness of the conductive material is the thinnest between the thin wires 31 and 32, and further the thin wires 31 and 32 from the Z. Is defined as the width of the thin lines 31 and 32 at half the height of Y1 and Y2. For example, when the parallel line pattern 3 includes the thin film portion 30 described above, the height of the thinnest portion in the thin film portion 30 can be set to Z. When the height of the thinnest portion of the conductive material between the thin wires 31 and 32 is 0, the line widths W1 and W2 of the thin wires 31 and 32 are the heights of the thin wires 31 and 32 from the surface of the substrate 2. It is defined as the width of the thin lines 31 and 32 at half the height of the lengths h1 and h2.

  Since the line widths W1 and W2 of the fine lines 31 and 32 constituting the parallel line pattern 3 can be made extremely thin as described above, the fine lines from the surface of the base material 2 are ensured from the viewpoint of securing a cross-sectional area and reducing resistance. The heights h1 and h2 of 31 and 32 are preferably higher. Specifically, the heights h1 and h2 of the thin wires 31 and 32 are preferably in the range of 50 nm to 5 μm.

  Furthermore, from the viewpoint of improving the stability of the parallel line pattern 3, the h1 / W1 ratio and the h2 / W2 ratio are preferably in the range of 0.05 or more and 1 or less, respectively.

  The height Z of the thinnest portion where the thickness of the conductive material is the thinnest between the thin wires 31 and 32, specifically, the height Z of the thinnest portion of the thin film portion 30 is the insulation between the thin wires 31 and 32. From the viewpoint of ensuring, it is preferably in the range of 10 nm or less. Although it is preferable not to include the thin film portion 30 (Z = 0), it is also preferable to include the thin film portion 30 in the range of 0 <Z ≦ 10 nm from the viewpoint of obtaining stability. When Z is not 0, the conductive material between the thin wires 31 and 32 is too thin (in other words, the conductive material is too small) from the viewpoint of preventing the opposite electrodes from being electrically coupled to each other. , 32 is not substantially energized, or a conductive material is not continuously formed between the thin wires 31, 32, and is not practically energized between the thin wires 31, 32.

  The h1 / Z ratio and h2 / Z ratio in the parallel line pattern 3 are each preferably 5 or more, more preferably 10 or more, and particularly preferably 20 or more.

  The interval I between the thin wires 31 and 32 can be appropriately adjusted according to the element to be formed, and is not particularly limited. In addition, the space | interval I of the thin wires 31 and 32 is defined as the distance between each largest protrusion part of the thin wires 31 and 32. FIG.

  In the parallel line pattern 3, it is preferable to consider the resistance values of the thin wire 31 and the thin wire 32 to be equal from the viewpoint of reducing a load caused by currents having different sizes flowing between the thin wire 31 and the fine wire 32. For that purpose, it is preferable to give the same shape (similar cross-sectional area) to the fine wire 31 and the fine wire 32. Specifically, the heights h1 and h2 of the fine wire 31 and the fine wire 32 are substantially equal. It is preferable to use a value. Similarly, it is preferable that the line widths W1 and W2 of the thin wire 31 and the thin wire 32 are substantially equal to each other.

  In this specification, “parallel lines” and “parallel” do not necessarily mean parallel in a strict sense, but at least over a certain length L (see FIG. 1B) in the line segment direction. This means that the thin wires 31 and 32 are not connected. Preferably, the thin wires 31 and 32 are substantially parallel over at least a certain length L in the line segment direction.

  The length L of the thin wires 31 and 32 in the line segment direction is preferably 5 times or more, and more preferably 10 times or more, the interval I between the thin wires 31 and 32.

  The length L and the interval I can be set corresponding to the formation length and formation width of the first line 2.

  The thin lines 31 and 32 constituting the parallel line pattern 3 have substantially the same line widths W1 and W2, and the line widths W1 and W2 are sufficiently narrower than the distance between the parallel lines (interval I). It is preferable that

  For the shape of the parallel line pattern 3 described above, the composition of the first line 2, the contact angle between the substrate and the first line 2, the concentration of the conductive material in the first line 2, the drying conditions, and the like are selected. Can be provided as appropriate.

  Moreover, the shape of the parallel line pattern 3 can be set as appropriate. As shown in FIG. 5, for example, the thin lines 31 and 32 constituting the parallel line pattern 3 may be straight lines (FIG. 5 ( a)) or wavy lines (FIG. 5B). Furthermore, the distance between the thin lines 31 and 32 constituting the parallel line pattern 3 may be partially increased (FIG. 5C), and the one end 33 and the other end 34 of the parallel line pattern 3 may be provided. The formation width (the width in the Y direction described above) of either or both (both in the illustrated example) may be larger than the distance between the thin wires 31 and 32 (FIG. 5D). Such a shape of the parallel line pattern 3 can be easily formed by appropriately setting the formation pattern of the first line 2.

  In the above description, the parallel line pattern 3 has been described, but the same applies to the case of other parallel line patterns (for example, in the case of the parallel line pattern 4 described above or in the case of parallel lines according to the second mode described later). can do.

  The substrate on which the comb-shaped electrode is formed is not particularly limited. For example, glass, plastic (polyethylene, polypropylene, acrylic, polyester, polyamide, etc.), metal (copper, nickel, aluminum, iron, etc. or alloy), ceramic And so on.

  Moreover, a base material can be suitably selected according to the kind of device to form. For example, when forming a surface acoustic wave element or a sensor as a device, a substrate made of a piezoelectric material can be suitably used as the substrate. Moreover, when forming a capacitor | condenser as a device, the base material which consists of an insulating material can be used suitably as a base material.

  Although it does not specifically limit as a conductive material contained in the parallel line pattern which concerns on this invention, A conductive fine particle, a conductive polymer, etc. can be illustrated preferably.

  The conductive fine particles are not particularly limited, but Au, Pt, Ag, Cu, Ni, Cr, Rh, Pd, Zn, Co, Mo, Ru, W, Os, Ir, Fe, Mn, Ge, Sn, Ga. In particular, fine particles such as In can be exemplified, and among them, use of fine metal particles such as Au, Ag, and Cu is more preferable because a circuit pattern having low electrical resistance and strong corrosion can be formed. From the viewpoint of cost and stability, metal fine particles containing Ag are most preferable. The average particle diameter of these metal fine particles is preferably in the range of 1 to 100 nm, more preferably in the range of 3 to 50 nm.

  It is also preferable to use carbon fine particles as the conductive fine particles. Preferable examples of the carbon fine particles include graphite fine particles, carbon nanotubes, fullerenes and the like.

  Although it does not specifically limit as a conductive polymer, (pi) conjugated system conductive polymer can be mentioned preferably.

  The π-conjugated conductive polymer is not particularly limited, and includes polythiophenes (including basic polythiophenes, the same applies hereinafter), polypyrroles, polyindoles, polycarbazoles, polyanilines, polyacetylenes, polyfurans, polyparaffins. A chain conductive polymer of phenylene vinylenes, polyazulenes, polyparaphenylenes, polyparaphenylene sulfides, polyisothianaphthenes, polythiazyls can be used. Of these, polythiophenes and polyanilines are preferable in that high conductivity and good precision patterning characteristics can be obtained. Most preferred is polyethylene dioxythiophene.

  More preferably, the conductive polymer used in the present invention comprises the above-described π-conjugated conductive polymer and a polyanion. Such a conductive polymer can be easily produced by chemical oxidative polymerization of a precursor monomer that forms a π-conjugated conductive polymer in the presence of an appropriate oxidizing agent, an oxidation catalyst, and a polyanion.

  The polyanion is a substituted or unsubstituted polyalkylene, a substituted or unsubstituted polyalkenylene, a substituted or unsubstituted polyimide, a substituted or unsubstituted polyamide, a substituted or unsubstituted polyester, and a copolymer thereof. It consists of a structural unit having a group and a structural unit having no anionic group.

  This polyanion is a solubilized polymer that solubilizes the π-conjugated conductive polymer in a solvent. The anion group of the polyanion functions as a dopant for the π-conjugated conductive polymer, and improves the conductivity and heat resistance of the π-conjugated conductive polymer.

  The anion group of the polyanion may be a functional group capable of undergoing chemical oxidation doping to the π-conjugated conductive polymer. Among them, from the viewpoint of ease of production and stability, a monosubstituted sulfate group, A monosubstituted phosphate group, a phosphate group, a carboxy group, a sulfo group and the like are preferable. Furthermore, from the viewpoint of the doping effect of the functional group on the π-conjugated conductive polymer, a sulfo group, a monosubstituted sulfate group and a carboxy group are more preferable.

  Specific examples of polyanions include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly-2-acrylamido-2-methylpropane sulfonic acid, polyisoprene sulfone. Examples include acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid, polymethacryl carboxylic acid, poly-2-acrylamido-2-methylpropane carboxylic acid, polyisoprene carboxylic acid, polyacrylic acid and the like. . These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient.

  Moreover, the polyanion which has F (fluorine atom) in a compound may be sufficient. Specifically, Nafion (made by Dupont) containing a perfluorosulfonic acid group, Flemion (made by Asahi Glass Co., Ltd.) made of perfluoro vinyl ether containing a carboxylic acid group, and the like can be mentioned.

  Among these, a compound having a sulfonic acid is more preferable since the ink ejection stability is particularly good when the ink jet printing method is used and high conductivity is obtained.

  Furthermore, among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylic acid ethylsulfonic acid, and polyacrylic acid butylsulfonic acid are preferable. These polyanions have the effect of being excellent in conductivity.

  The degree of polymerization of the polyanion is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of solvent solubility and conductivity.

  A commercially available material can also be preferably used for the conductive polymer. For example, a conductive polymer (abbreviated as PEDOT / PSS) made of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid is H.264. C. It is commercially available from Starck as the CLEVIOS series, from Aldrich as PEDOT-PASS 483095, 560598, and from Nagase Chemtex as the Denatron series. Polyaniline is also commercially available from Nissan Chemical as the ORMECON series.

  The conductive material may be dissolved or dispersed in the conductive material-containing liquid.

  The conductive material-containing liquid can contain the conductive material in a solvent composed of water, an organic solvent, or a mixture thereof.

  The organic solvent is not particularly limited. For example, 1,2-hexanediol, 2-methyl-2,4-pentanediol, 1,3-butanediol, alcohols such as propylene glycol, diethylene glycol diethyl ether, diethylene glycol monobutyl ether Ethers such as can be exemplified, and one or two or more may be used in combination.

  It is also preferable that the conductive material-containing liquid contains a surfactant. Thereby, the contact angle between the conductive material-containing liquid and the substrate can be adjusted. The surfactant is not particularly limited, but a silicon surfactant or the like can be used. Silicon surfactants are those in which the side chain or terminal of dimethylpolysiloxane is polyether-modified, such as KF-351A and KF-642 made by Shin-Etsu Chemical, BYK347 and BYK348 made by Big Chemie are commercially available. Yes.

  Moreover, the conductive material-containing liquid may contain, for example, a solid content such as a metal oxide or a polymer in addition to the conductive material described above.

  The conductive material-containing liquid can contain various additives as long as the effects of the present invention are not impaired.

  The method of applying the conductive material-containing liquid on the substrate is not particularly limited, and for example, a printing method can be preferably exemplified.

  As a printing method, a generally known method can be used, and an inkjet method, a screen printing method, a relief printing method, an intaglio printing method, an offset printing method, a flexographic printing method and the like can be preferably exemplified.

  As the ink jet method, a generally known method can be used. A piezo method in which an ink droplet is ejected by deforming an ink channel by vibration of a piezoelectric element, and a heating element is provided in the ink channel. The thermal system that generates heat and generates bubbles and discharges ink droplets in response to pressure changes in the ink flow path due to the air bubbles, electrostatically attracts ink by charging the ink in the ink flow path A preferable example is an electrostatic suction method for discharging ink droplets. In this specification, the expression “ink” may be used for the sake of convenience, but it is needless to say that it does not need to contain a pigment / dye and may be a liquid.

  The method for applying the insulating material on the base material is not particularly limited, and any of the above-described methods for conducting the conductive material-containing liquid can be used as appropriate. Among these, for example, a printing method can be preferably exemplified, and an inkjet method is particularly preferable.

  In the above example, the example in which the extraction electrode is formed after the comb electrode is formed is shown, but the present invention is not limited to this, and the extraction electrode can be formed at an arbitrary timing. For example, it is also preferable to form the comb electrode after forming the extraction electrode in advance.

  The formed comb-like electrode and / or extraction electrode is preferably subjected to heating, baking, or heating by electromagnetic waves. Thereby, the resistance value can also be lowered.

  6 and 7 are explanatory views for explaining a second aspect of the method for forming a comb-shaped electrode, and showing a plan view of a base material on which the comb-shaped electrode is formed.

  As shown in FIG. 6A, a conductive material-containing liquid is applied on the substrate 1. Thus, the first lines 9 made of the conductive material-containing liquid and the second lines 10 made of the conductive material-containing liquid are alternately formed on the substrate 1. In the illustrated example, a plurality of (three in the illustrated example) first lines 9 and a plurality of (three in the illustrated example) second lines 10 are formed.

  The conductive material-containing liquid for forming the first line 9 and the conductive material-containing liquid for forming the second line 10 may be the same in the conductive material and the solvent contained therein. It may be different or different.

  The first line 9 and the second line 10 are parallel to each other, and the intervals between adjacent lines are equally arranged.

  Further, the first line 9 and the second line 10 are formed at positions shifted from each other by a predetermined interval in the Y direction.

  Next, the first line 9 and the second line 10 are dried. That is, the liquid in the conductive material-containing liquid constituting the first line 9 and the second line 10 is evaporated. At this time, in the drying process, the conductive material in the conductive material-containing liquid is deposited on the edge, and as shown in FIG. 6B, the first parallel lines including the thin lines 111 and 112 parallel to each other are obtained. A second parallel line pattern 12 including the pattern 11 and fine lines 121 and 122 parallel to each other is formed.

  In the first parallel line pattern 11, the thin parallel lines 111 and 112 generated from one line 9 are closed at both ends. That is, the thin wires 111 and 112 are connected to each other by the end portion 113 on one end side and the end portion 114 on the other end side of the first parallel line pattern 11.

  Similarly, in the second parallel line pattern 12, the thin parallel lines 121 and 122 generated from one line 10 are closed at both ends. That is, the thin wires 121 and 122 are connected to each other by the end portion 123 on one end side and the end portion 124 on the other end side of the second parallel line pattern 12.

  The end portion 113 on the one end side of the first parallel line pattern 11 is arranged on the outer side (the left side in the drawing) than the end portion 123 on the one end side of the second parallel line pattern 12.

  The end portion 124 on the other end side of the second parallel line pattern 12 is arranged on the outer side (right side in the drawing) than the end portion 114 on the other end side of the first parallel line pattern 11.

  The thin parallel lines 111 and 112 constituting the first parallel line pattern 11 and the thin parallel lines 121 and 122 constituting the second parallel line pattern 12 are parallel to each other.

  The fine lines 111 and 112 constituting the first parallel line pattern 11 and the fine lines 121 and 122 constituting the second parallel line pattern 12 are alternately arranged in the Y direction. The distance between the fine lines 112 and 121 adjacent in the Y direction and the distance between the fine lines 111 and 122 adjacent in the Y direction are equal.

  As shown in FIG. 7, the first extraction electrode 13 is formed so as to cross the end portion 113 on one end side of the plurality of first parallel line patterns 11 in the Y direction as necessary. Similarly, the second extraction electrode 14 is formed so as to cross the end portion 124 on the other end side of the plurality of second parallel line patterns 12 in the Y direction.

  As described above, the comb-like electrode composed of the fine lines 111 and 112 constituting the first parallel line pattern 11 and the comb-like shape composed of the fine lines 121 and 122 constituting the second parallel line pattern 12 are opposite to each other. It is possible to form a comb-shaped electrode combined with the electrode so that the comb-tooth portions are engaged with each other so as not to be coupled to each other.

  Also in the second aspect of the method for forming a comb-shaped electrode, as in the first aspect described above, the fine wires forming the comb-like electrode and the counter electrode are self-adhesive in the drying process. Since it is formed by being deposited on the edge in an organized manner, it can be formed more easily than when it is formed by, for example, photolithography. In addition, the thin line can be made sufficiently thin beyond the limit of thinning by a normal printing method. Thereby, the usage-amount of an electroconductive material can be reduced, for example.

  In particular, in the second aspect of the method for forming a comb-shaped electrode, the insulating layer used in the first aspect described above is formed by forming the first parallel line pattern and the second parallel line pattern apart from each other in the Y direction. There is no need to provide it. Also, a process of simultaneously drying the first line 9 and the second line 10 and simultaneously forming the first parallel line pattern 11 and the second parallel line pattern 12 can be preferably applied. Therefore, an effect that the comb-shaped electrode can be formed more easily is obtained.

  In the second embodiment, it is also preferable to dry the second wire 10 after drying the first wire 9. Thereby, compared with the case where the 1st line 9 and the 2nd line 10 are dried simultaneously, the influence of a vapor pressure can be excluded suitably and the effect which can improve pattern accuracy further is acquired. Specifically, for example, after the first line 9 is formed, the first line 9 is dried to obtain the parallel line pattern 11, and then the second line 10 is formed and then dried to obtain the parallel line pattern 12. It is to do.

  The present invention is not limited to the first aspect and the second aspect described above, and at least the electrodes of the comb teeth portion provide a conductive material-containing liquid to form a line segment, and then control the drying process. What is necessary is just to be formed using the method of forming the parallel line pattern containing an electroconductive material in self-organization.

  In the example described above, as a comb-teeth electrode, a conductive material-containing liquid is applied to form a line segment, and then a drying process is controlled to form a parallel line pattern including a conductive material in a self-organizing manner. Although the case where the one formed by the method is used as it is is mainly shown, it is not limited to this. The electrode of the comb-tooth part should just be formed using at least the method of forming this parallel line pattern. The parallel line pattern formed by the method of forming such a parallel line pattern can be appropriately processed to form a comb-teeth electrode. Such a treatment is not particularly limited. For example, the formed parallel line pattern may be subjected to a firing treatment, or a plating treatment such as electroless plating or electroplating may be performed to form a comb. It is also preferable to utilize it as an electrode of a tooth part. By appropriately performing such processing, it is possible to further reduce resistance, stabilize conductivity, and the like.

  The comb-shaped electrode obtained by the method for forming a comb-shaped electrode of the present invention can be suitably used as an electrode in various devices.

  Although it does not specifically limit as a device, Sensors, such as a surface acoustic wave element and a gas sensor, a capacitor | condenser, etc. can be illustrated especially preferable. Moreover, the comb-shaped electrode obtained by the method for forming a comb-shaped electrode of the present invention can be suitably used as an electrode of a battery (for example, a secondary battery, a solar battery, etc.).

  Although the example of a structure is shown below about the case where the comb-shaped electrode obtained by the comb-shaped electrode formation method of this invention is utilized for a surface acoustic wave element, it is not limited by this example of a structure.

  As shown in the example of FIG. 8, the surface acoustic wave element (surface acoustic wave filter) includes a plurality of sets (two sets in the illustrated example) of comb-shaped electrodes 16 and 17 on a piezoelectric material substrate 15 that is a substrate. It can be configured by arranging. As the comb electrodes 16 and 17, the comb electrodes of the present invention can be used.

  Although the piezoelectric material which comprises the piezoelectric material base material 15 is not specifically limited, A polyvinylidene fluoride film etc. other than a quartz plate and PZT can be used preferably.

  The interval C between the comb teeth is preferably in the range of 5 μm to 10 μm. The comb tooth interval C is a pitch when the comb-shaped electrodes and the comb-shaped counter electrodes are alternately arranged.

  The line width of the comb teeth is preferably in the range of 3 μm to 20 μm. The line width of the comb teeth refers to W1 or W2 described with reference to FIG.

  The intervals and line widths of the comb teeth are not limited to the above, and can be appropriately set according to the target frequency that passes through the filter.

  Although the example of a structure is shown below about the case where the comb-shaped electrode obtained by the comb-shaped electrode formation method of this invention is utilized for a sensor, it is not limited by this example of a structure.

  As shown in the example of FIG. 9, the sensor (here, an example of a gas sensor) includes a plurality of sets (two sets in the illustrated example) of comb-shaped electrodes 19 and 20 on the piezoelectric material substrate 18. Further, a gas adsorbent layer 21 can be arranged between the comb electrodes 19 and 20. As the comb electrodes 19 and 20, the comb electrodes of the present invention can be used.

  By using such a gas sensor, the target gas concentration can be known based on the detection frequency.

  In the above example, an example of a gas sensor provided with the gas adsorbent layer 21 is shown. However, by providing an adsorbent layer that adsorbs an arbitrary substance, the target substance can be used without being limited to gas. For example, if an adsorbent layer that adsorbs a specific solute or dispersoid is provided in place of the gas adsorbent layer 21, a sensor that detects the concentration of the target solute or dispersoid in the liquid can be obtained.

  Although the example of a structure is shown below about the case where the comb-shaped electrode obtained by the comb-shaped electrode formation method of this invention is utilized for a capacitor | condenser, it is not limited by this example of a structure.

  As shown in the example of FIG. 10, the capacitor can be configured by providing a comb-shaped electrode 23 on an insulating base material 22 and further providing a dielectric material layer 24 thereon. As the comb electrode 23, the comb electrode of the present invention can be used.

  The method for forming the dielectric material layer 24 is not particularly limited. For example, it is preferable to form the dielectric material layer 24 by applying a dielectric paint on the insulating base material 22 and drying by heating.

  In the example of FIGS. 8 to 10, the case where the comb-shaped electrode formed according to the first aspect is used as the electrode of each device is not limited to this. For example, the comb-shaped electrode formed according to the second aspect is used. Also function as each device.

  In the above description, the configuration described for one embodiment can be applied to other embodiments as appropriate.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

  In the following Examples 1 to 3, the comb-shaped electrode was formed by the method according to the first aspect of the present invention.

Example 1 Surface Acoustic Wave Device
As shown in FIG. 8, on the polyvinylidene fluoride film (piezoelectric material substrate), two sets of metal comb electrodes having a comb spacing of 5 μm and a line width of 3 μm were formed, and a current of 130 MHz was passed from the left end, and at the right end Similarly, a high frequency current of 130 MHz was detected.

(Example 2; sensor)
As shown in FIG. 9, two sets of comb-shaped electrodes were formed on a piezoelectric material substrate, and a gas adsorbent layer was applied and formed at the center of the substrate to form a gas sensor.
When the obtained sensor was placed in the chamber and the target gas concentration was changed, it was confirmed that the detection frequency changed according to the change.
By creating a calibration curve that correlates the change in the target gas concentration with the change in the detection frequency, and using this calibration curve, the target gas concentration can be calculated for the target gas having an unknown concentration.

(Example 3; condenser)
As shown in FIG. 10, a comb-shaped electrode was formed on a PET film (insulating substrate), and a dielectric coating was applied on the electrode, followed by heating and drying to form a dielectric layer, thereby forming a capacitor.
When the electric capacity of the obtained capacitor was measured, an electric capacity of 15 nF was confirmed.

  In the above examples, the comb-shaped electrode formed according to the first aspect was used as the electrode of each device. However, it was confirmed that even if the comb-shaped electrode formed according to the second aspect was used, it functions as each device.

1: Substrate 2: First line 3: First parallel line pattern 31, 32: Fine line 33: End part on one end side 34: End part on the other end side 35: Extension part on one end side 4: Insulating layer 41 : One end side insulating layer 42: other end side insulating layer 5: second line 6: second parallel line pattern 61 and 62: fine line 63: one end side end 64: other end side end 65: other end Side extension 7: First extraction electrode 8: Second extraction electrode 9: First line 10: Second line 11: First parallel line pattern 111, 112: Fine line 113: End on one end side 114: End portion on the other end side 12: Second parallel line pattern 121, 122: Fine line 123: End portion on one end side 124: End portion on the other end side 13: First extraction electrode 14: Second extraction electrode

Claims (9)

A comb-shaped electrode combined with a comb-shaped electrode and a comb-shaped counter electrode so as not to be coupled to each other on a substrate,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process Comb-shaped electrode characterized by utilizing.   2. The comb electrode according to claim 1, wherein an insulating material layer is inserted between the opposite electrodes so that the opposite electrodes are not bonded to each other.   2. The comb electrode according to claim 1, wherein the parallel line patterns are spaced apart from each other so that the opposite electrodes are not coupled to each other. A comb-shaped electrode combined with a comb-shaped electrode and a comb-shaped counter electrode so as not to be coupled to each other on a substrate,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process A method of forming a comb-shaped electrode, which is characterized by being utilized.   5. The method of forming a comb-shaped electrode according to claim 4, further comprising a step of arranging an insulating material layer so as to be inserted between the opposite electrodes so that the opposite electrodes are not bonded to each other.   The device provided with the comb-shaped electrode in any one of Claims 1-3. A surface acoustic wave device comprising a plurality of comb electrodes on a piezoelectric substrate,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process A surface acoustic wave device characterized by being utilized. A gas sensor comprising a plurality of comb electrodes on a piezoelectric substrate, and a gas adsorption layer between the plurality of comb electrodes,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process A gas sensor characterized by utilizing it. A capacitor comprising a comb electrode on a substrate, and a dielectric material layer on the comb electrode,
As an electrode of a comb tooth part, after forming a line segment by applying a liquid containing a conductive material, the one formed by a method of forming a parallel line pattern including a conductive material in a self-organizing manner by controlling the drying process Capacitor characterized by utilizing.

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